Yukon meteorite revolutionizes astrobiology

Early life forms may have hitched a ride to Earth on meteorites, said top NASA scientist Mike Zolensky of the Johnson Space Centre in Texas.

Evidence for this was found in the Tagish Lake meteorite that was discovered after it blazed across the dawn skies of the Yukon and northern British Columbia then landed on Tagish Lake, January 18, 2000, said Zolensky from Houston.

“There are a couple special things about this meteorite,” he said.

“One is that it was recovered frozen and preserved, the second thing was — kind of miraculously almost — it turned out to be a kind of rare meteorite; they only fall about once a decade.

“These are very water- and organic-rich meteorites and of those meteorites this is probably one of the most organic rich.

“It contains a very high amount of carbon, minerals like in lagoons and in the ocean, and also hydrocarbon globules in the meteorite.”

Zolensky described the globules as “little condos” that contain what might be the basic ingredients for early life — carbon and hydrocarbon.

Because of the type of carbon found in these globules, NASA scientists know that they didn’t form here on Earth and that they didn’t even form in our solar system.

“They formed somewhere else in interstellar space,” said Zolensky.

“These are actually grains of interstellar molecules — little structures, little bubbles — that formed long before our solar system did and they somehow missed or escaped being changed while our planets were forming and the solar system was forming.

“The little globules managed to survive all that time.”

These globules aren’t fossils, they aren’t living, but they could have provided a place for early life to move into.

Until Yukon outdoorsman Jim Brook discovered the Tagish Lake meteorite, this kind of early life-form environment was only seen in laboratory experiments.

Because Brook kept the meteor frozen after he found it, scientists caught their first glimpse of what they had previously only guessed existed.

NASA scientists believe the Tagish Lake meteorite is 4.5 billion years old. They believe the carbon found in the meteorite is even older than that.

This would make the carbon and hydrocarbon matter older than the Earth itself.

Other fragments of the Tagish Lake meteor orbited past Jupiter on its way to Earth.

The meteorite fragments, bought from Brook, have been returned to Canada.

They are being kept at the University of Alberta and the Royal Ontario Museum for further study.

Chris Herd, at the University of Alberta, is hoping to receive government funding to study these fragments further.

Not all the fragments are the same; some have globules on them, like the Tagish Lake meteor studied at NASA, and some are a fine black dust, said Herd from Edmonton.

Much study has yet to be done on the meteorite fragments, such as how much, and in what way, their process of falling to Earth may have contaminated them, said Herd.

These fragments are unlike any others found before, due to their state of preservation and the amount of organic material found on them, he said.

If Canadian scientists can study these fragments thoroughly, that will put Canada at the forefront of meteorite study, he added. Perhaps when other meteorites are discovered, the scientific world will look to Canada to lead the research.

“I think it’s extremely exciting and this could really catapult Canada into the forefront in the research of meteorites and extraterrestrial rocks,” said Herd.

“Because if we can demonstrate to the world that we can do good science with the Tagish Lake meteorites, that means we can do good science on just about anything — whether they’re samples that come back from the moon or from Mars or whatever … this is just as good as sending a spacecraft out to the outer asteroid belt and bringing a sample back.”